U.S. patent application number 17/487057 was filed with the patent office on 2022-01-13 for coil device.
This patent application is currently assigned to TDK CORPORATION. The applicant listed for this patent is TDK CORPORATION. Invention is credited to Yoshihiro KAWASAKI, Munehito NISHIMURA, Setu TSUCHIDA.
Application Number | 20220013274 17/487057 |
Document ID | / |
Family ID | 1000005869202 |
Filed Date | 2022-01-13 |
United States Patent
Application |
20220013274 |
Kind Code |
A1 |
KAWASAKI; Yoshihiro ; et
al. |
January 13, 2022 |
COIL DEVICE
Abstract
A coil device includes: a core including a winding core part and
a flange part at an axial end part of the winding core part, a coil
part including a first wire and a second wire wound around the
winding core part, a first terminal electrode, formed on a flange
part mounting surface and a lead-out part of the first wire is
connected, and a second terminal electrode, formed on the mounting
surface of the flange part spaced apart from the first terminal
electrode and a lead-out part of the second wire is connected, in
which the flange part includes a concave part, recessed from the
upper surface of the flange part and from an outer end surface of
the flange part in order to have bottoms. The coil device is easy
to connect a wire and has excellent bonding strength even when the
connecting part becomes the mounting surface.
Inventors: |
KAWASAKI; Yoshihiro; (Tokyo,
JP) ; NISHIMURA; Munehito; (Tokyo, JP) ;
TSUCHIDA; Setu; (Tsuruoka-city, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TDK CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
TDK CORPORATION
Tokyo
JP
|
Family ID: |
1000005869202 |
Appl. No.: |
17/487057 |
Filed: |
September 28, 2021 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
16027865 |
Jul 5, 2018 |
11164692 |
|
|
17487057 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01F 27/29 20130101;
H01F 17/04 20130101; H01F 27/2828 20130101; H01F 27/24 20130101;
H01F 27/292 20130101; H01F 27/2823 20130101; H01F 17/045 20130101;
H01F 41/10 20130101; H01F 41/064 20160101 |
International
Class: |
H01F 27/24 20060101
H01F027/24; H01F 41/064 20060101 H01F041/064; H01F 27/29 20060101
H01F027/29; H01F 27/28 20060101 H01F027/28; H01F 17/04 20060101
H01F017/04; H01F 41/10 20060101 H01F041/10 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 11, 2017 |
JP |
2017-135365 |
Dec 18, 2017 |
JP |
2017-242234 |
Claims
1. A coil device comprising: a core comprising a winding core part
and a flange part at an axial end part of the winding core part, a
coil part comprising a first wire and a second wire wound around
the winding core part, a first terminal electrode, on a mounting
surface of the flange part and to which a lead-out part of the
first wire is connected, and a second terminal electrode, on the
mounting surface of the flange part spaced apart from the first
terminal electrode and to which a lead-out part of the second wire
is connected, wherein the flange part comprises a concave part and
a wall, the a bottom surface of the concave part is located closer
to one of the first terminal electrode and the second terminal
electrode than to another of the first terminal electrode and the
second terminal electrode between the first terminal electrode and
the second terminal electrode, and the wall includes opposite side
surfaces defined by the inner edge surface of the flange part and
the concave part and extends upwardly from the bottom surface of
the concave part between the concave part and the inner edge
surface of the flange part.
2. The coil device according to claim 1, wherein the lead-out part
of the second wire extends obliquely from an outer periphery of the
winding core part through the second terminal electrode toward the
concave part, when viewed from the mounting surface.
3. The coil device according to claim 1, wherein an end part of the
lead-out part of the second wire is provided on the second terminal
electrode close to the concave part.
4. The coil device according to claim 2, wherein an end part of the
lead-out part of the second wire is provided on the second terminal
electrode close to the concave part.
5. The coil device according to claim 1, wherein an inclined part,
inclined from an outer periphery of the winding core part toward
the first terminal electrode, is on an inner end surface of the
flange part, the lead-out part of the first wire extends along an
inclined surface of the inclined part from the outer periphery of
the winding core part toward the first terminal electrode, and the
wall is between the inclined part and a side wall surface of the
concave part.
6. The coil device according to claim 2, wherein an inclined part,
inclined from the outer periphery of the winding core part toward
the first terminal electrode, is on an inner end surface of the
flange part, the lead-out part of the first wire extends along an
inclined surface of the inclined part from the outer periphery of
the winding core part toward the first terminal electrode, and the
wall is between the inclined part and a side wall surface of the
concave part.
7. The coil device according to claim 1, wherein an outer shape of
the flange part as viewed from a front and an outer shape of the
flange part as viewed from a back substantially coincide with each
other, when the core is reversed.
8. The coil device according to claim 2, wherein an outer shape of
the flange part as viewed from a front and an outer shape of the
flange part as viewed from a back substantially coincide with each
other, when the core is reversed.
9. A coil device comprising: a core comprising a winding core part,
a first flange part at an axial end part of the winding core part,
and a second flange part at another axial end part of the winding
core part, a coil part in which a first wire and a second wire are
wound around the winding core part, a first terminal electrode, on
a mounting surface of the first flange part and connected to one
lead-out part of the first wire, a second terminal electrode, on
the mounting surface of the first flange part spaced apart from the
first terminal electrode and connected to one lead-out part of the
second wire, a third terminal electrode, on the mounting surface of
the second flange part and connected to a second lead-out part of
the second wire, and a fourth terminal electrode, on the mounting
surface of the second flange part spaced apart from the third
terminal electrode and connected to a second lead-out part of the
first wire, wherein the first flange part comprises a concave part
and a wall, a bottom surface of the concave part is located closer
to one of the first terminal electrode and the second terminal
electrode than to another of the first terminal electrode and the
second terminal electrode between the first terminal electrode and
the second terminal electrode, and the wall includes opposite side
surfaces defined by the inner edge surface of the flange part and
the concave part and extends upwardly from the bottom surface of
the concave part between the concave part and the inner edge
surface of the flange part.
10. The coil device according to claim 9, further comprising: a
first inclined part of the first flange part, inclined from an
outer periphery of the winding core part toward the first terminal
electrode and on an inner end surface of the first flange part, and
a second inclined part of the second flange part, inclined from the
outer periphery of the winding core part toward the third terminal
electrode and on an inner end surface of the second flange part,
wherein the one lead-out part of the first wire extends along an
inclined surface of the first inclined part of the first flange
part from the outer periphery of the winding core part toward the
first terminal electrode, and the second lead-out part of the
second wire extends along an inclined surface of the second
inclined part of the second flange part from the outer periphery of
the winding core part toward the third terminal electrode.
11. A core comprising: a winding core part and a flange part
provided at an axial end part of the winding core part, wherein the
flange part comprises a concave part and a wall, when viewed from a
direction parallel to the axial direction of the winding core part,
a bottom surface of the concave part is located closer to one end
of the flange part than the other end of the flange part, and the
wall includes opposite side surfaces defined by the inner edge
surface of the flange part and the concave part and extends
upwardly from the bottom surface of the concave part between the
concave part and the inner edge surface of the flange part.
Description
RELATED APPLICATIONS
[0001] This is a Continuation Application of U.S. patent
application Ser. No. 16/027,865 filed Jul. 5, 2018, which claims
the benefit of Japanese Patent Application Nos. 2017-135365, filed
Jul. 11, 2017, and 2017-242234, filed Dec. 18, 2017. The disclosure
of the prior applications is hereby incorporated by reference
herein in its entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention relates to a coil device used as, for
example, an inductor.
2. Description of the Related Art
[0003] Patent Document 1 discloses a coil device on which a
terminal electrode, having a wire connected on the side opposite to
the mounting surface, is formed. With the coil device described in
Patent Document 1, there is a possibility that sufficient bonding
strength between the coil device and the circuit board cannot be
ensured when the terminal electrode and the wire are connected on
the mounting surface.
PRIOR ART
[0004] Patent Document 1: JP 2009-147159A
DISCLOSURE OF THE INVENTION
Means for Solving the Problems
[0005] The present invention has been made in view of such
circumstances, and an object of the present invention is to provide
a coil device which is easy to connect a wire and has excellent
bonding strength even when the connecting part becomes a mounting
surface.
[0006] To achieve the above object, a coil device of the first
object of the invention includes:
[0007] a core including a winding core part and a flange part
provided at an axial end part of the winding core part,
[0008] a coil part including a first wire and a second wire wound
around the winding core part,
[0009] a first terminal electrode, formed on a mounting surface of
the flange part and a lead-out part of the first wire is connected,
and
[0010] a second terminal electrode, formed on the mounting surface
of the flange part spaced apart from the first terminal electrode
and a lead-out part of the second wire is connected, in which
[0011] the flange part includes a concave part, recessed from the
mounting surface of the flange part and from an outer end surface
of the flange part in order to have bottoms.
[0012] To achieve the above object, the core of the invention
includes:
[0013] a winding core part and
[0014] a flange part provided at an axial end part of the winding
core part, in which
[0015] the flange part includes a concave part, recessed from a
mounting surface of the flange part and from an outer end surface
of the flange part in order to have bottoms.
[0016] In the coil device according to the first aspect of the
present invention and the core according to the present invention,
the flange part includes the concave part, recessed from the
mounting surface of the flange part and from the outer end surface
of the flange part in order to have bottoms. For this reason, at
the time of cutting after connecting the wire, for example, a
cutting position of the wire is arranged on the mounting surface
side of the concave part, and the cutting is performed so as to
enter the cutting tool to the bottom from the mounting surface of
the concave part.
[0017] When the wire is cut while pressing a lead-out part with the
cutting tool on the flange part, the flange part may be damaged,
and it is not easy to cut the wire. In the present invention, since
the wire can be cut in the above-described manner, the wire can be
easily connected and cut.
[0018] Further, in the present invention, the concave part is
recessed in order to have bottoms and is not extended to an inner
end surface. Therefore, the outer end surface and the inner end
surface of the flange part are not in communication with each other
and are partitioned by a wall. Therefore, when cutting the wire, it
can prevent cutting another wire incorrectly.
[0019] Further, with the above-described configuration, even if the
concave part is formed in the flange part, the volume of the flange
part does not become extremely small, and the inductance of the
coil device does not decrease. In addition, even if an external
force is applied to the flange from the first terminal electrode
side or the second terminal electrode side, the flange part has a
high strength capable of withstanding the force.
[0020] Further, by leading out the wire toward the concave part, it
becomes possible to draw the wire obliquely on the electrode and
bond the wire at the end part of the terminal electrode. Therefore,
good solder wettability can be obtained except for the bonding part
between the wire and the terminal electrode, the area of the
electrode surface can be sufficiently large, and it becomes
possible to increase the bonding strength between the coil device
and the circuit board.
[0021] It is preferable that the concave part is located close to
the second terminal electrode between the first terminal electrode
and the second terminal electrode, and the lead-out part of the
second wire extends obliquely from an outer periphery of the
winding core part through the second terminal electrode toward the
concave part, when viewed from the mounting surface.
[0022] With such configuration, the second wire can be bonded to
the end part of the second terminal electrode. In this case, a good
solder wettability can be obtained except at the bonding part
between the lead-out part of the second wire and the second
terminal electrode. Thus, the area of the electrode surface can be
sufficiently large and the bonding strength between the coil device
and the circuit board can be increased.
[0023] It is preferable that an end part of the lead-out part of
the second wire is provided on the second terminal electrode close
to the concave part. With such an arrangement, the second wire is
arranged on the mounting surface side of the concave part when the
second wire is cut. Thus, it becomes possible to cut the second
wire while the cutting tool enters toward the bottom from the
mounting surface of the concave part.
[0024] It is preferable that, an inclined part inclined from the
outer periphery of the winding core toward the first terminal
electrode is formed on the inner end surface provided opposite to
the outer end surface of the flange part, the led-out part of the
first wire extends along the inclined surface of the inclined part
from the outer periphery of the winding core part toward the first
terminal electrode, and a wall is formed between the bottom from
the outer end surface of the concave part and the inclined
part.
[0025] In this way, by forming the inclined part on the inner end
surface, it is possible to draw out the first wire along the
inclined surface of the inclined part, and no excessive load is
generated on the lead-out part of the first wire. In addition,
since a wall is formed between the bottom from the outer end
surface of the concave part and the inclined part, the concave part
and the inclined part do not communicate with each other, and when
cutting the second wire, the first wire is prevented from being
cut.
[0026] It is preferable that an outer shape of the flange part as
viewed from the front and an outer shape of the flange part as
viewed from the back substantially coincide with each other, when
the core is reversed. In this way, it becomes possible to form the
terminal electrode on both front and back of the flange part.
[0027] In order to achieve the above object, a coil device of the
second object of the invention includes:
[0028] a core including a winding core part, a first flange part
provided at an axial end part of the winding core part, and a
second flange part provided at the other axial end part of the
winding core part,
[0029] a coil part in which a first wire and a second wire are
wound around the winding core part,
[0030] a first terminal electrode, formed on a mounting surface of
the first flange part and connected to one lead-out part of the
first wire, a second terminal electrode, formed on the mounting
surface of the first flange part spaced apart from the first
terminal electrode and connected to one lead-out part of the second
wire,
[0031] a third terminal electrode, formed on the mounting surface
of the second flange part and connected to the other lead-out part
of the second wire, and
[0032] a fourth terminal electrode, formed on the mounting surface
of the second flange part spaced apart from the third terminal
electrode and connected to the other lead-out part of the first
wire, in which
[0033] the first flange part includes a concave part, recessed from
the mounting surface of the first flange part and from an outer end
surface of the first flange part in order to have bottoms.
[0034] The coil device may include:
[0035] a first inclined part of the first flange part, inclined
from an outer periphery of the winding core toward the first
terminal electrode and formed on an inner end surface opposite to
the outer end surface of the first flange part, and
[0036] a second inclined part of the second flange part, inclined
from the outer periphery of the winding core toward the third
terminal electrode and formed on an inner end surface opposite to
an outer end surface of the second flange part, in which
[0037] the one lead-out part of the first wire extends along an
inclined surface of the first inclined part of the first flange
part from the outer periphery of the winding core part toward the
first terminal electrode,
[0038] and the other lead-out part of the second wire extends along
an inclined surface of the second inclined part of the second
flange part from the outer periphery of the winding core part
toward the third terminal electrode. With such configuration, it
becomes possible to equalize the line length of the coil composed
of the first wire and the line length of the coil made of the
second wire.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1A is an entire perspective view of the coil device
according to the first embodiment of the invention.
[0040] FIG. 1B is a planar view of the coil device shown in FIG.
1A.
[0041] FIG. 1C is a side view of the coil device shown in FIG. 1A,
viewed from the direction of 1C.
[0042] FIG. 2A is a perspective view showing the producing steps of
the coil device shown in FIG. 1A.
[0043] FIG. 2B is a perspective view showing a subsequent step of
FIG. 2A.
[0044] FIG. 2C is a perspective view showing a subsequent step of
FIG. 2B.
[0045] FIG. 2D is a perspective view showing a subsequent step of
FIG. 2C.
[0046] FIG. 2E is a perspective view showing a subsequent step of
FIG. 2D.
[0047] FIG. 2F is a perspective view showing a subsequent step of
FIG. 2E.
[0048] FIG. 2G is a perspective view showing a subsequent step of
FIG. 2F.
[0049] FIG. 2H is a perspective view showing a subsequent step of
FIG. 2G.
[0050] FIG. 3A is another perspective view showing the producing
steps of the coil device according to the second embodiment of the
present invention.
[0051] FIG. 3B is a perspective view showing a subsequent step of
FIG. 3A.
[0052] FIG. 3C is a perspective view showing a subsequent step of
FIG. 3B.
[0053] FIG. 4 is another perspective view showing the step of FIG.
3C
[0054] FIG. 5 is an overall perspective view of a modified example
of the core of the coil device shown in FIG. 1A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0055] Hereinafter, the present invention will be described based
on the embodiments shown by figures.
The First Embodiment
[0056] As shown in FIG. 1A, coil device 1 according to an
embodiment of the invention includes a drum core 10 and a coil part
30, wound around a winding core part 12 of the drum core 10.
[0057] In the following description, the X axis indicates a
direction parallel to the winding axis of the winding core 12 of
the drum core 10 in a plane parallel to the mounting surface on
which the coil device 1 is mounted. As with the X axis, the Y axis
is in a plane parallel to the mounting surface and is perpendicular
to the X axis. The Z axis is in normal direction to the mounting
surface.
[0058] The drum core 10 has the winding core part 12 and a pair of
flange parts 14a, 14b provided at both ends in the X axis direction
of the winding core part 12. One of the flange parts 14a (the first
flange part) is provided at one end of the winding core part 12 in
the axial direction. The other flange part 14b (the second flange
part) is provided at the other end of the winding core part 12 in
the axial direction and faces the flange part 14a. In the following
description, when it is unnecessary to particularly distinguish the
flange parts 14 a and 14 b, they are collectively referred to as
"flange part 14". The winding core part 12 has a winding axis in
the X axis direction and has a substantially hexagonal cross
section elongated in the Y axis direction. Each of the flange parts
14 has the same shape, but they may be different from each other.
In the present embodiment, the respective flange parts 14 is
provided so as to be point symmetrical to each other. Although the
cross sectional shape of the winding core part 12 is substantially
hexagonal in the present embodiment, it may be rectangular,
circular, or substantially octagonal, and its cross sectional shape
is not particularly limited.
[0059] As shown in FIG. 1A, the first wire 31 and the second wire
32 wound around the winding core part 12, and constitute the coil
part 30 formed by winding one or more layers of the wires 31, 32.
The wires 31, 32 are constituted by such as coated conducting
wires, and have a configuration in which a core material made of a
good conductor is covered with an insulating coating film. In the
present embodiment, the cross sectional areas of the conductor part
of the wires 31, 32 may be the same or different. Further, the coil
part 30 may be formed by winding one wire in one or more layers, or
may be formed by winding three or more wires in one or more
layers.
[0060] In the present embodiment, although the number of turns of
the wires 31 and 32 are substantially the same, they may be
different depending on the use. It should be noted that "the number
of turns of the wires 31 and 32 are substantially the same" refers
to the ratio of the number of turns is within the range of 0.75 to
1/0.75, and preferably one.
[0061] The outer shape of each flange part 14 is a substantially
rectangular parallelepiped shape (substantially rectangular shape)
in the Y axis direction. And these flange parts 14 are arranged so
as to be substantially parallel to each other with a predetermined
interval in the X axis direction. As shown in FIG. 1B, when viewing
the flange part 14 from the mounting surface side (the Z axis upper
side in the present embodiment), the flange part 14 is formed so
that its four corners are rounded. The cross sectional (Y-Z cross
section) shape of the flange part 14 may be a circular shape or a
substantially octagonal shape, and its cross sectional shape is not
particularly limited.
[0062] As shown in FIG. 1B, the flange part 14 has an upper surface
14A, a lower surface 14B, an inner end surface 14C, an outer end
surface 14D, the first lateral side surface 14E, and the second
lateral side surface 14F. The upper surface 14A is a surface on the
upper side of the flange part 14. The lower surface 14B is a
surface opposite to the upper surface 14A. The inner end surface
14C is a surface on the winding core part 12 side. The outer end
surface 14D is a surface opposite to the inner end surface 14C. The
first lateral side surface 14E is orthogonal to the upper surface
14A and the inner end surface 14C, and is on the side of the first
terminal electrode 41 described later. The second lateral side
surface 14F is perpendicular to the upper surface 14A and the inner
end surface 14C and is the face on the side of the second terminal
electrode 42.
[0063] In the present embodiment, the upper surface 14A becomes the
mounting surface (a ground surface) when the coil device 1 is
mounted on such as a circuit board. In the illustrated example, the
second lateral side surface 14F of one flange part 14 flushes with
the first lateral side surface 14E of the other flange part 14.
However, there may be a deviation in Y axis direction between the
lateral side surfaces 14E and 14F.
[0064] The first terminal electrode 41 is formed on the upper
surface 14A (the mounting surface) of the flange part 14. The first
terminal electrode 41 formed on the first flange part 14a and the
first terminal electrode (the third terminal electrode) 41 formed
on the second flange part 14b have the same configuration. As shown
in FIG. 1B and FIG. 1C, according to the present embodiment, the
first terminal electrode 41 includes the first upper surface
electrode part 410 and the first side surface electrode part 411,
which are electrically connected. More specifically, the first
upper surface electrode part 410 is parallel to the X-Y plane and
is formed at one end of the upper surface 14A of the flange part 14
in the Y axis direction. A part of the first upper surface
electrode part 410 also extends to the first inclined part 141
described later. The first side surface electrode part 411 is a
surface parallel to the Y-Z plane and is formed on the end surface
14D of the flange part 14. By forming the first side surface
electrode part 411 on the flange part 14, it is possible to form a
sufficient solder fillet on the first terminal electrode 41.
[0065] The first connecting part 311, which is a connecting part of
the first wire 31 with the lead-out part 310, is formed in the
first upper electrode part 410 formed on the first flange part 14a.
A first connecting part 321, which is a connecting part of the
second wire 32 to the lead-out part 320, is formed on the first
upper surface electrode part 410 formed on the second flange part
14b. The connection parts 311, 321 are formed by thermocompression
bonding the lead-out parts 310, 320 to the first upper surface
electrode part 410. In the present embodiment, the first upper
surface electrode parts 410 and 420 also function as a mounting
part that is connected to face the circuit board (not shown). More
specifically, a part of the first upper surface electrode parts
410, 420 where the first connecting parts 311, 321 are not formed
functions as a good bonding surface of solder with electrodes
(lands) of the circuit board.
[0066] In general, the solder wettability decreases at the
thermocompression bonded part. Therefore, it is preferable that the
first connecting parts 311, 321 are preferably provided at the end,
and but not in the central part of the first upper surface
electrode parts 410, 420. Thereby, it is possible to ensure a
sufficiently large area of the first upper surface electrode part
410, 420 having excellent solder wettability, to increase the
bonding strength (fixing strength) between the coil device and the
circuit substrate. In addition, even when the coil device 1 is
downsized, it is possible to sufficiently secure the fixing
strength with the circuit board.
[0067] On the upper surface 14A (the mounting surface) of the
flange part 14, the second terminal electrode 42 is formed at a
predetermined interval (spaced apart) from the first terminal
electrode 41 along the Y axis direction. The second terminal
electrode 42 formed in the first flange part 14a and the second
terminal electrode (the fourth terminal electrode) 42 formed in the
second flange part 14b have the same configuration. The distance
between the first terminal electrode 41 and the second terminal
electrode 42 is not particularly limited as long as insulation is
secured.
[0068] According to the present embodiment, the second terminal
electrode 42 includes the second upper surface electrode part 420
and the second side surface electrode part 421, which are
electrically connected. More specifically, the second upper surface
electrode part 420 is parallel to the X-Y plane and is formed at
one end of the upper surface 14A of the flange part 14 in the Y
axis direction. A part of the second upper surface electrode part
420 also extends to the second inclined part 142 and the third
inclined part described later. The second side surface electrode
part 421 is a surface parallel to the Y-Z plane and is formed on
the end surface 14D of the flange part 14. By forming the first
side surface electrode part 411 on the flange part 14, it is
possible to form the sufficient solder fillet on the second
terminal electrode 42.
[0069] The second upper surface electrode part 420 formed on the
first flange part 14a is formed with the second connecting wire
part 321 which is the connecting part with the lead out part 320 of
the second wire 32. The second upper surface electrode part 420
formed on the second flange part 14b is formed with the first
connecting part 311 which is a connecting part of the first wire 31
with the lead-out part 310. The connection parts 311, 321 are
formed by thermocompression bonding the lead-out parts 310, 320 to
the second upper surface electrode part 420. In the present
embodiment, the second upper surface electrode part 420 also
functions as the mounting part that is connected to be opposed to
the surface of the circuit board (not shown). More specifically,
the part of the second upper surface electrode part 420 where the
connecting parts 311 and 321 are not formed functions as a good
bonding surface of the solder to the electrode (land) of the
circuit board.
[0070] Note that it is preferable that the connecting parts 311 and
321 are provided not at the center but on the end part of the
second upper surface electrode part 420. Thereby, it becomes
possible to secure a sufficiently large area, where it is excellent
in solder wettability. And it is possible to increase the fixing
strength between the coil device and the circuit board. In
addition, even when the coil device 1 is downsized, it is possible
to sufficiently secure the fixing strength with the circuit
board.
[0071] On the inner end surface 14C positioned opposite to the
outer end surface 14D of the first flange part 14a, the first
inclined part (the first inclined part of the first flange part)
141 inclined from the outer periphery (the outer periphery on the
side of second terminal electrode 42) of the winding core part 12
(the first flange part side inclined part) is formed. Similarly, on
the inner end surface 14C positioned opposite to the outer end
surface 14D of the second flange part 14b, the first inclined part
(the first inclined part of the second flange part) 141 inclined
from the outer periphery (the outer periphery on the side of the
second terminal electrode 42) of the winding core part 12 (a first
flange part side inclined part) is formed. As shown in FIG. 2A, the
first inclined part 141 is inclined so as to gradually descend from
the first terminal electrode 41 side toward the second terminal
electrode 42 side. The first inclined part 141 is formed in a range
between the intersection line 14C1, formed by the inner end surface
14C and the outer periphery of the winding core part 12, and the
upper surface 14A.
[0072] When viewed from the upper surface 14 side, the first
inclined part 141 has an outer shape of a substantially triangular
shape (approximately right triangle in the illustrated example),
and gradually narrows toward the second terminal electrode 42 side.
In the present embodiment, the lead-out part 310 of the first wire
31 extends obliquely from the outer periphery of the winding core
part 12 toward the first terminal electrode 41 of the first flange
part 14a along the inclined surface of the first inclined part 141.
The lead-out part 320 of the second wire 32 extends obliquely from
the outer periphery of the winding core part 12 toward the first
terminal electrode 41 of the second flange part 14b along the
inclined surface of the first inclined part 141.
[0073] As shown in FIGS. 1A and 1B, the second inclined part 142 is
formed on the inner end surface 14C of the flange part 14. The
second inclined part 142 is inclined so as to gradually descend
toward the winding core part 12 along the X axis direction. The
second inclined part 142 is formed in a range between the
intersection line 14C1 formed by the inner end surface 14C and the
outer periphery of the winding core part 12 and the upper surface
14A.
[0074] In the present embodiment, the lead-out part 320 of the
second wire 32 extends obliquely from the outer periphery of the
winding core part 12 toward the second terminal electrode 42 of the
first flange part 14a along the inclined surface of the second
inclined part 142. Further, the lead-out part 310 of the first wire
31 extends obliquely from the outer periphery of the winding core
part 12 toward the second terminal electrode 42 of the second
flange part 14b along the inclined surface of the second inclined
part 142. Therefore, it is preferable that the lead-out parts 310
and 320 pass through the end part of the second terminal electrode
42 and sufficiently secure the area of the second upper surface
electrode part 420 having excellent solder wettability as described
above.
[0075] The third inclined part 143 is formed on the first lateral
side surface 14E of the flange part 14. The third inclined part 143
is inclined so as to gradually descend toward the outer side of the
flange part 14 along the Y axis direction.
[0076] A fourth inclined part 144 is formed on the second lateral
side surface 14F of the flange part 14. The fourth inclined part
144 is inclined so as to gradually descend toward the outside of
the flange part 14 along the Y axis direction.
[0077] As shown in FIG. 2A, on the inner end surface 14C of the
flange part 14, a step part 146 is formed at the bonding part with
the winding core part 12. The step part 146 is used as a passage
for smoothly leading out the lead-out parts 310, 320 of the wires
31, 32 to the second upper electrode part 420 of the second
terminal electrode 42.
[0078] As shown in FIGS. 1A and 1B, the flange part 14 has the
concave part 140 recessed from the mounting surface (the upper
surface 14A) of the flange part and from an outer end surface of
the flange part in order to have bottoms. That is, the concave part
140 (groove) for opening the upper surface 14A side and the outer
end surface 14D side of the flange part 14 is formed at the corner
part between the upper surface 14A and the outer end surface 14D of
the flange part 14.
[0079] The concave part 140 has a first side wall 140a, a second
side wall 140b, a third side wall 140c, and a fourth side wall
140d. The first side wall 140a is a side wall on the side opposite
to the inner end surface 14C and corresponds to the bottom from the
outer end surface 14D of the concave part 140. The second side wall
140b is a side wall on the side opposite to the first lateral end
surface 14E. The third side wall 140c is a side wall on the side
opposite to the second lateral end surface 14F and is on the side
opposite to the second side wall 140b. The fourth side wall 140d is
a side wall on the side opposite to the inner end surface 14C and
corresponds to the bottom from the upper surface (mounting surface)
14A of the concave part 140.
[0080] In the present embodiment, the concave part 140 is located
between the first terminal electrode 41 and the second terminal
electrode 42. In the present embodiment, the concave part 140 is
provided closer to the second terminal electrode 42 than the first
terminal electrode 41. A gap of a predetermined length is formed
between the concave part 140 and the second terminal electrode 42.
The gap may be omitted.
[0081] With such arrangement, the lead-out parts 310, 320 of the
wires 31, 32 obliquely extends from the outer circumference (more
precisely, the step part 146) of the winding core part 12, through
the inclined surface of the second inclined part 142 and the second
terminal electrode 42 (more precisely, the end part of the second
terminal electrode 42 in the X axis direction), and toward the
concave part 140, when viewed from the upper surface (the mounting
surface) 14A side. End parts of the lead-out parts 310 and 320 of
the wires 31 and 32 are provided on the second terminal electrode
42 near the concave part 140 (near the third side wall 140 c).
[0082] As shown in FIG. 1B, the concave part 140 has a
substantially square shape when viewed from the upper surface 14A
side. However, the shape of the concave part 140 is not limited
thereto, and may be, for example, a substantially rectangular shape
or a substantially circular shape when viewed from the upper
surface 14A side.
[0083] As shown in FIG. 1B, the first side wall 140 a, the second
side wall 140 b, and the third side wall 140 c of the concave part
140 are tapered surfaces, respectively. And as shown in FIG. 1C,
the width in the X axis direction and the width in the Y axis
direction gets narrower as the upper surface 14A gets closer to the
lower surface 14B at the concave part 140. Note that the first side
wall 140a, the second side wall 140b, and the third side wall 140c
of the concave part 140 may be surfaces perpendicular to the upper
surface 14A.
[0084] As shown in FIG. 1A, a wall 145 is formed between the first
side wall 140a (the bottom from the outer end surface 14D) and the
first inclined part 141, respectively of the concave part 140. The
wall 145 connects the first terminal electrode 41 side and the
second terminal electrode 42 side of the concave part 140 along the
Y axis direction. Therefore, a region of the height H1 (see FIG.
1C) is formed continuously through the wall 145 between the first
terminal electrode 41 side and the second terminal electrode 42
side having the concave part 140 in between.
[0085] The first terminal electrode 41 and the second terminal
electrode 42 are composed such as of a metal paste baking film or a
metal plating film. For the terminal electrodes 41 and 42, for
example, Ag paste is applied to the surfaces of the upper surface
14A and the outer end surface 14D of the flange part 14 and baked
thereof, and then the surface is subjected to, for example,
electrolytic plating or electroless plating to form a plating
film.
[0086] The material of the metal paste is not particularly limited,
and examples thereof include Cu paste and Ag paste. Further, the
plating film may be a single layer or a multiple layer, and plating
films such as Cu plating, Ni plating, Sn plating, Ni--Sn plating,
Cu--Ni--Sn plating, Ni--Au plating, Au plating and the like are
exemplified. The thickness of the terminal electrodes 41 and 42 is
not particularly limited, but it is preferably 0.1 to 15 .mu.m.
[0087] In manufacturing the coil device 1, first, the drum core 10
and the wires 31, 32 are prepared. As the wires 31 and 32, for
example, a core material made of a good conductor such as copper
(Cu) is covered with an insulating material such as imide-modified
polyurethane and the outermost surface is covered with a thin resin
film such as polyester can be used.
[0088] As the magnetic material constituting the drum core 10, for
example, a magnetic material having a relatively high magnetic
permeability such as a Ni--Zn based ferrite, an Mn--Zn based
ferrite, a metal magnetic material, or the like is exemplified.
These magnetic material powders are pressed and sintered, whereby
the drum core 10 is produced. At that time, as shown in FIG. 2A, in
the drum core 10, the recessed part 140, the first inclined part
141, the second inclined part 142, the third inclined part 143, and
the fourth inclined part 144 are integrally formed in each part of
the flange part 14. Further, in the drum core 10, the winding core
part 12 and the pair of flange parts 14 are integrally formed.
[0089] Next, a metal paste is applied to the flange part 14 of the
drum core 10 and baked thereof at a predetermined temperature.
Then, by applying electrolytic plating or electroless plating on
the surface thereof, the first terminal electrode 41 and the second
terminal electrode 42 as shown in FIG. 2B are formed.
[0090] Next, the drum core 10 and the wires 31, 32 on which the
terminal electrodes 41, 42 are formed are set at a winding machine
(not shown). And as shown in FIG. 2C, the first wire 31 (lead-out
part 310) is lead out from the tip of the nozzle 50 and connected
to the first upper surface electrode part 410 of the first terminal
electrode 41. As a result, the first connecting part 311 is formed
at the connecting part between the first upper electrode part 410
and the first wire 31.
[0091] Similarly, the second wire 32 (the lead-out part 320) is
drawn out from the tip of the nozzle 50 and connected to the second
upper electrode part 420 of the second terminal electrode 42. As a
result, the second connecting part 321 is formed at the connecting
part between the second upper surface electrode part 420 and the
second wire 32.
[0092] A method for the connection is not particularly limited. For
example, a heater chip is pressed so as to sandwich the wire 31 or
32 between itself and the terminal electrode 41 or 42, and the
wires 31, 32 are thermocompression bonded. Since the insulating
material covering the core wires of the wires 31 and 32 is melted
by heat during thermocompression bonding, it is not necessary to
remove the coating on the wires 31 and 32.
[0093] Next, as shown in FIG. 2D, an unnecessary part of the first
wire 31 (the lead-out part 310) protruding from the first upper
surface electrode part 410 (the first terminal electrode 41) is cut
by the cutting tool 60. When the unnecessary part of the lead-out
part 310 is cut, the cut part of the lead-out part 310 is provided
around the third inclined part 143, and the cutting tool 60 is
placed (located) so that its side surface substantially flushes
with the first lateral side surface 14E.
[0094] Then, at that position, the cutting tool 60 is lowered along
the first lateral side surface 14E in the Z axis direction. As a
result, it is possible to cut the cut part of the lead-out part 310
without bringing the cutting tool 60 into contact with the corner
part of the upper surface 14A and the first lateral side surface
14E respectively of the flange part 14, and the flange part 14 can
be prevented from being damaged.
[0095] Similarly, an unnecessary part of the second wire 32 (the
lead-out part 320) protruding from the second upper surface
electrode part 420 (the second terminal electrode 42) is cut by the
cutting tool 60. At the time of cutting the unnecessary part of the
lead-out part 320, the cut part of the lead-out part 320 is
arranged on the mounting surface side of the recessed part 140 and
at least a part of the cutting tool 60 is provided (positioned)
above the upper surface 14A of the flange part 14, such that the
side surface thereof substantially flushes with the third side wall
140c.
[0096] Then, at that position, the cutting tool 60 is lowered in
the Z axis direction along the third side wall 14c toward the
fourth side wall 140d. At this time, at least a part of the cutting
tool 60 enters the inside of the concave part 140 from the outside
of the concave part 140, cuts the cut part of the lead-out part 320
on the mounting surface side of the concave part 140, then enters
the inside of the concave part 140 as it is. Therefore, it is
possible to cut the cut part of the lead-out part 320 without
bringing the cutting tool 60 into contact with the upper surface
14A of the flange part 14, preventing the flange part 14 from being
damaged.
[0097] Next, as shown in FIG. 2E, the first wire 31 (the lead-out
part 310) is drawn obliquely to the outer periphery of the winding
core part 12 along the inclined surface of the first inclined part
141 and wound around the winding core part 12. Similarly, the
second wire 32 (the lead-out part 320) is drawn obliquely to the
outer periphery of the winding core part 12 along the inclined
surface of the second inclined part 420 and wound around the
winding core part 12 to form the coil part 30. Then, the wires 31,
32 (the lead-out parts 310, 320) are obliquely drawn from the outer
periphery of the winding core part 12 so as to pass through the
connecting parts 420, 410 of the terminal electrodes 42, 41, and
hooked and fixed to each pole 70 so as not to slack.
[0098] Next, as shown in FIG. 2F, the first wire 31 is connected to
the second upper surface electrode part 420 of the second terminal
electrode 42. As a result, the first connecting part 311 is formed
at a connecting part between the second upper surface electrode
part 420 and the first wire 31.
[0099] Similarly, the second wire 32 is connected to the first
upper surface electrode part 410 of the first terminal electrode
41. As a result, a second connecting part 321 is formed at the
connecting part between the first upper surface electrode part 410
and the second wire 32.
[0100] Next, as shown in FIG. 2G, unnecessary parts of the first
wires 31 (the lead-out part 310) protruding from the second upper
surface electrode part 420 (the second terminal electrode 42) are
cut in the same manner as described in FIG. 2D with the cutting
tool 60. Similarly, unnecessary parts of the second wire 32 (the
lead-out part 320) protruding from the first upper surface
electrode part 410 (the first terminal electrode 41) is cut by the
cutting tool 60.
[0101] Next, as shown in FIG. 2H, the plate-shaped core 20 is
placed on the lower surface 14B of the flange part 14. The lower
surface 14B is formed of a flat surface, and it is easy to install
the plate-shaped core 20. The plate-shaped core 20 is a flat
rectangular parallelepiped having a flat surface, and has a
function of increasing the inductance of the coil device 1. The
plate-shaped core 20 is preferably composed of the same magnetic
member as the drum core 10, but it may be composed of separate
members. The plate-shaped core 20 is not necessarily made of a
magnetic material and may be made of a non-magnetic material such
as a synthetic resin.
[0102] In the present embodiment, the flange part 14 is formed with
the concave part 140 that is recessed so that the bottom remains
from the upper surface (mounting surface) 14A and the outer end
surface 14D of the flange part 14. Therefore, at the time of
cutting after connecting the second wire 32, for example, the cut
point of the second wire 32 is provided on the side respectively of
the upper surface 14A of the concave part 140, and the cutting tool
is moved toward the bottom from the upper surface 14A of the
concave part 140.
[0103] Further, in the present embodiment, the concave part 140 is
recessed so that the bottom remains from the outer end surface 14D,
and is not formed so as to extend to the inner end surface 14C.
Therefore, the outer end surface 14D of the flange part 14 and the
inner end surface 14C do not communicate with each other and are
partitioned by the wall 145. Therefore, it is possible to prevent
erroneously cutting the first wire 31 when cutting the second wire
32.
[0104] Further, with the above-described configuration, even if the
concave part 140 is formed in the flange part 14, the volume of the
flange part 14 does not become extremely small, and the inductance
of the coil device 1 never decreases. Even if an external force is
applied to the flange part 14 from the first terminal electrode 31
side or the second terminal electrode 32 side, the flange part 14
has a high strength capable of withstanding thereof is
provided.
[0105] In the present embodiment, the concave part 140 is provided
close to the second terminal electrode 42 between the first
terminal electrode 41 and the second terminal electrode 42. And the
lead-out part 320 of the second wire 32 extends obliquely from the
outer periphery of the winding core part 12 through the second
terminal electrode 42 toward the concave part 140, when viewed from
the upper surface 14 A side.
[0106] That is, in the present embodiment, by pulling the second
wire 32 toward the concave part 140, the second wire 32 is drawn
obliquely on the second terminal electrode 42, and it becomes
possible to bond the second wires 32 to the end of the second
terminal electrode 42. Therefore, a good solder wettability can be
obtained except for the second connecting part 321 which is the
bonding part between the second wire 32 and the second terminal
electrode 42, and the area of the surface of the second terminal
electrode 42 is sufficiently large. Thus, it is possible to
increase the bonding strength between the coil device 1 and the
circuit board.
[0107] Further, in the present embodiment, the end part of the
lead-out part 320 of the second wire 32 is provided on the second
terminal electrode 42 close to the concave part 140. With such an
arrangement, when cutting the second wire 32, the second wire 32 is
arranged on the concave part 140 at the upper surface 14A side so
that the second wire 32 can be cut by allowing the cutting tool to
enter from the upper surface 14A of the concave part 140 toward the
bottom.
[0108] In the present embodiment, the first inclined part 141
inclined from the outer periphery of the winding core part 12
toward the first terminal electrode 42 is formed on the inner end
surface 14C positioned opposite to the outer end surface 14D of the
flange part 14. The lead-out part 310 of the first wire 32 extends
along the inclined surface of the first inclined part 141 from the
outer periphery of the core part 12 toward the first terminal
electrode 41, and the wall 145 is formed between the bottom of the
outer end surface 14D of the concave part 140 and the first
inclined part 141.
[0109] By thus forming the first inclined part 141 on the inner end
surface 14C, the first wire 32 can be lead out along the inclined
surface of the first inclined part 141. Thus, an excessive load
does not generate at the lead-out part 310 of the first wire 31.
Further, since a wall is formed between the bottom from the outer
end surface 14D of the concave part 140 and the first inclined part
141, the concave part 140 and the first inclined part 141 are not
communicated with each other, and it is possible to prevent
erroneously cutting the first wire 31 at the time of cutting the
wire 32.
The Second Embodiment
[0110] The coil devices 1A according to the second embodiment shown
in FIGS. 3A to 3C have the same configuration and exhibit the same
operational effects, as the coil device 1 according to the first
embodiment except for the following. Each member of the coil device
1A shown in FIGS. 3A to 3C corresponds to each members of the coil
device 1 according to the first embodiment shown in such as FIGS.
2E to 2 G, and the same reference numerals are given to the
corresponding members. The explanation is partly omitted.
[0111] The coil device 1A has the coil part 30A. The coil part 30A
has the first layer formed by the first wire 31 and the second
layer provided on the outer periphery of the first layer and formed
with the second wire 32.
[0112] In manufacturing the coil device 1A, each step shown in
FIGS. 2A to 2D is carried out in the same manner as described in
the first embodiment. Next, as shown in FIG. 3A, the first wire 31
and the second wire 32 are wound around the winding core part 12 in
two layers. Next, the lead-out part 310 of the first wire 31 is
drawn out to the second upper surface electrode part 420 of the
second terminal electrode 42 of the flange part 14b, and connected
as shown in FIG. 3B to form the first connecting part 311.
Similarly, the lead-out part 320 of the second wire 32 is lead out
to the first upper surface electrode part 410 of the first terminal
electrode 41 of the flange part 14b, and connected as shown in FIG.
3B to form the second connecting part 321. Next, as shown in FIG.
3C, an unnecessary part of the first wire 31 (lead-out part 310)
protruding from the second upper surface electrode part 420 and an
unnecessary part of the second wire 32 (lead-out part 320)
protruding from the first upper surface electrode part 410 are cut
by the cutting tool 60.
[0113] As shown in FIG. 4, the unnecessary part of the second wire
32 (the lead-out part 320) may be cut at a position separated from
the third inclined surface 143 in the Y axis direction. In that
case, an unnecessary part of the second wire 32 may remain at the
tip of the second connecting part 321 as shown in FIG. 4. The
detailed illustration is omitted, but the same is applied to
cutting the unnecessary part of the first wire 31 (the lead-out
part 310) inside the concave part 140.
[0114] It should be noted that the present invention is not limited
to the above-described embodiments, and can be variously modified
within the scope of the invention.
[0115] In the above embodiment, the widths W3, W4 and the height H2
of the concave part 140 shown in FIG. 1B are not particularly
limited, and may be appropriately changed according to the size of
the cutting tool. However, from the viewpoint of easily entering at
least a part of the cutting tool inside the concave part 140, it is
preferable that the widths W3, W4 and the height H2 are large, and
from the viewpoint of improving the inductance of the coil device
1, the widths W3, W4 and the height H2 are preferably as small as
possible.
[0116] Specifically, the ratio W3/W1 of the width W3 in the X axis
direction of the concave part 140 on the upper surface 14A to the
width W1 in the X axis direction of the flange part 14 is
preferably 0.1 to 0.6, more preferably 0.3 to 0.5. The width W4 in
the Y axis direction of the concave part 140 on the upper surface
14A may be determined according to the distance between the first
terminal electrode 41 and the second terminal electrode 42. In the
illustrated example, the width W4 is substantially the same as the
width W3, but it may be different. The ratio H2/H1 of the height H2
in the Z axis direction of the concave part 140 shown in FIG. 1C to
the height H1 in the Z axis direction of the flange part 14 is
preferably 0.5 to 0.9, more preferably 0.6 to 0.8.
[0117] The minimum width W5 between the concave part 140 and the
first inclined part 141 shown in FIG. 1B is not particularly
limited, and may be appropriately determined considering the widths
W1 and W3. However, the minimum width W5 between the concave part
140 and the first inclined part 141 is at least 0.05 mm or
more.
[0118] The size of the coil device 1 is not particularly limited,
but the length L in X axis direction is 1.15 to 1.35 mm, the width
W2 in Y axis direction is 0.9 to 1.1 mm, and the height H1 (see
FIG. 1C) in Z axis direction is 0.45 to 0.53 mm. The ratio W6/W2 of
Y axis direction width W6 of the winding core part 12 shown in FIG.
2A to the Y axis direction width W2 of the flange parts 14, 14
shown in FIG. 1B is preferably 0.6 to 0.9.
[0119] Further, according to the first embodiment, each lead-out
part 310 of the first wire 31 may be connected to the first
terminal electrode 41 of the first flange part 14a and the first
terminal electrode 41 of the second flange part 14b. Similarly, the
lead-out parts 320 of the second wire 32 may be respectively
connected to the second terminal electrode 42 of the first flange
part 14a and the second terminal electrode 42 of the second flange
part 14b. In this case, for example, before or after forming the
coil part 30, the first wire 31 and the second wire 32 are made to
intersect (twist the pair of wires 31, 32), whereby the positional
relation of the first wire 31 and the second wire 32 may be
reversed from the example shown in FIG. 1A.
[0120] In the second embodiment, the respective lead-out parts 310
of the first wire 31 may be respectively connected to the first
terminal electrode 41 of the first flange part 14a and the first
terminal electrode 41 of the second flange part 14b. Similarly, the
lead-out parts 320 of the second wire 32 may be respectively
connected to the second terminal electrode 42 of the first flange
part 14a and the second terminal electrode 42 of the second flange
part 14b.
[0121] In the above embodiments, as shown in FIG. 2A, the concave
part 140 and the first inclined part 140 are formed only on the
upper surface 14A of the flange part 14. However, as shown in FIG.
5, they may be formed also on the lower surface 14B of the flange
part 14. In this case, when the core 10 is reversed, it is
preferable to make the direction in which the first groove part 141
extends and the relative position of the concave part 140 of the
upper surface (a front surface) 14A coincide with the same of lower
surface (a back surface) 14B, in order to make the outer shape of
the flange part 14 as viewed from the upper surface 14A
substantially coincide with the outer shape of the flange part 14
as viewed from the lower surface 14B.
[0122] Further, in each of the above embodiments, as shown in FIG.
2B, the case where the first terminal electrode 41 is made by the
first upper surface electrode part 410 and the first side surface
electrode part 411 is exemplified, however, the first side surface
electrode part 411 may be omitted. Similarly, for the second
terminal electrode 42, the second side surface electrode part 421
may be omitted.
[0123] In each of the above embodiments, the range of the first
upper surface electrode part 410 may be expanded to the outer side
in the Y axis direction of the third inclined part 143, and the end
part in the Y axis direction of the flange part 14 may be covered
with the first upper surface electrode part 410. Further, the range
of the first side surface electrode part 411 may be extended to the
outer side in the Y axis direction of the flange part 14, and the
end part in the Y axis direction of the flange part 14 may be
covered with the first side surface electrode part 411.
[0124] Similarly, the range of the second upper surface electrode
part 420 may be extended to the outer side of the fourth inclined
part 144 in the Y axis direction, and the end part of the flange
part 14 in the Y axis direction may be covered with the second
upper surface electrode part 420. Further, the range of the second
side surface electrode part 421 may be expanded to the outside of
the flange part 14 in the Y axis direction, and the end part of the
flange part 14 in the Y axis direction may be covered with the
second side surface electrode part 412.
NUMERICAL REFERENCES
[0125] 1, 1A . . . Coil Device [0126] 10 . . . Drum Core [0127] 12
. . . Winding Core Part [0128] 14, 14a, 14b . . . Flange Part
[0129] 14A . . . Upper [0130] 14B . . . Lower [0131] 14C . . .
Inner End Surface [0132] 14C1 . . . Intersection Line [0133] 14D .
. . Outer End Surface [0134] 14E . . . First Lateral Side Surface
[0135] 14F . . . Second Lateral Side Surface [0136] 140 . . .
Concave Part [0137] 140a . . . First Side Wall [0138] 140b . . .
Second Side Wall [0139] 140c . . . Third Side Wall [0140] 140d . .
. Fourth Side Wall [0141] 141 . . . First inclined part [0142] 142
. . . Second inclined part [0143] 143 . . . Third inclined part
[0144] 144 . . . Fourth inclined part [0145] 145 . . . Wall [0146]
146 . . . Step Part [0147] 20 . . . Plate-Shaped Core [0148] 30,
30A . . . Coil Part [0149] 31 . . . The First Wire [0150] 310 . . .
Lead-Out Part [0151] 311 . . . The First Connecting Part [0152] 32
. . . The Second Wire [0153] 320 . . . Lead-Out Part [0154] 321 . .
. The Second Connecting Part [0155] 41 . . . The First Terminal
Electrode [0156] 410 . . . The First Upper Surface Electrode Part
[0157] 411 . . . The First Side Surface Electrode Part [0158] 42 .
. . The Second Terminal Electrode [0159] 420 . . . The Second Upper
Surface Electrode Part [0160] 421 . . . The Second Side Surface
Electrode Part [0161] 50 . . . Nozzle [0162] 60 . . . Cutting Tool
[0163] 70 . . . Pole
* * * * *